Re: how to program the statement by simtalk2.0 which the function returns boolean?

You can let Plant Simulation convert SimTalk 1.0 code to SimTalk 2.0 :Insert an empty Method and open it in the Method Editor.In the ribbon deactivate the setting "Tools > New Syntax".Enter the SimTalk 1.0 code (note that you will need "is do end;") and click Apply.Activate "Tools > New Syntax".